About Octal to Number
The Octal to Number converter transforms octal (base-8) values into their decimal (base-10) equivalent. This is especially useful for system administrators and developers who encounter octal values in Unix file permissions, legacy system configurations, and embedded programming contexts.
When you see a file permission like 755 or 644 on a Linux system, those are octal values. This tool instantly converts them to decimal, helping you understand the underlying numeric value and verify permission calculations.
Developers working with legacy computing systems, certain microcontrollers, and aerospace platforms frequently encounter octal values in memory addresses and configuration registers. Manual conversion is error-prone, especially for longer octal strings. Paste the value and get the decimal result immediately.
The converter accepts octal strings containing digits 0 through 7, with optional leading minus sign for negative values. Invalid digits (8, 9, letters) are automatically stripped. It handles octal strings up to 53 bits, covering the full range of JavaScript safe integers.
All processing is entirely client-side. No data is uploaded, stored, or transmitted. The tool is free, unlimited, and requires no registration.
How to Use Octal to Number
Type or paste an octal string (digits 0-7) into the input field.
The decimal value appears instantly below.
Click Copy to copy the number to your clipboard.
Use a leading minus sign for negative octal values.
Key Benefits
Frequently Asked Questions
What digits are valid in octal?
Octal uses only digits 0 through 7. The digits 8 and 9 are not valid in octal and will be stripped from the input.
How are negative numbers handled?
A leading minus sign indicates a negative value. For example, -100 in octal converts to -64 in decimal.
What is the longest octal string supported?
The tool supports octal strings up to 53 bits, covering the full range of JavaScript safe integers.
Is my input uploaded anywhere?
No. All conversion happens entirely in your browser. Nothing is stored or transmitted.
Is the Octal to Number tool free?
Yes, it is completely free with no registration required.